The present invention relates to an all-steel clothing for a flat card or roller card for processing textile fibres, which has a sawtooth wire having teeth formed one after another in the wire running direction, the tooth contour of the teeth being defined, starting from a tooth base, as at least transitioning into a tooth back, further transitioning into a tooth tip portion, further transitioning into a tooth face and again transitioning into a subsequent tooth base, and the tooth tip portion being formed having a predetermined tooth tip length in the wire running direction.
An all-steel clothing of the same generic kind for a flat card or roller card is known from EP 1 576 215 B1. The sawtooth wire has teeth formed one after another in the wire running direction; a tooth tip portion referred to as a head surface is defined by a length which corresponds to at least 15% of the length of the tooth pitch; and the tooth pitch is defined as the spacing between the tooth tips of two adjacent teeth. The tooth tip of each tooth therein is formed by the transition from the tooth tip portion into the tooth face.
All-steel clothing should, on the one hand, have a long service life; on the other hand, the clothing should allow good orientation and cleaning of the textile fibres forming the yarns. For that purpose, the surface of the tooth tip portion, defined by the width of the teeth in the head region and the length of the tooth tip portions, should be as small as possible. If the surface is re-ground because of wear on the sawtooth wire, the surface of the tooth tip portion becomes larger, and consequently it is no longer possible to obtain a satisfactory carding result. This is especially due to the fact that, for construction of the teeth, and also especially for interacting with the textile fibres, the flank angle of the tooth back must be flatter than the face angle of the tooth face. If the surface area of the tooth tip portion is re-ground too often as a result of being ground down, the surface becomes larger owing to a reduction in the tooth height until the all-steel clothing can no longer be used.